1. Field of the Invention
This invention relates to a foldable frame assembly for suspending a machine above a ground surface, more particularly to a foldable frame assembly which can be folded conveniently and rapidly with less effort.
2. Description of the Related Art
Referring to FIG. 1, in co-pending U.S. patent application Ser. No. 11/012,385, the applicant disclosed a foldable frame assembly 10 that includes a base frame 11, a tabletop unit 12, a prop member 13, a front locking unit 14, a bracing member 15, and a rear locking unit 16. The base frame 11 has a wheel-carrying end provided with two wheels 113 rotatably mounted thereon, a handgrip end 112, and an intermediate portion 111. The tabletop unit 12 has a front pivot end pivotally mounted on the intermediate portion 111 so as to enable the tabletop unit 12 to turn relative to the base frame 11. The prop member 13 has an upper pivot end 131 pivotally mounted on the intermediate portion 111, and a flange 132 having first and second positioning slots 1321, 1322. The front locking unit 14 has a seat 141 secured on the handgrip end 112 of the base frame 11, and a spring-loaded retaining pin 142 movably disposed on the seat 141 such that the retaining pin 142 engages respectively the first and second positioning slots 1321, 1322 in unfolded and folded positions. The bracing member 15 has a lower end pivotally mounted on the wheel-carrying end of the base frame 11, and an upper end which is slidably coupled to the tabletop unit 12. The rear locking unit 16 includes a seat 161 secured on the tabletop unit 12, and a spring-loaded actuating member 162 movably mounted on the seat 161 so as to engage a first engaging portion (not shown) and a second engaging portion 151 of the bracing member 15, respectively, in the unfolded and folded positions.
During folding of the frame assembly 10, the user has to hold the tabletop unit 12 with one hand, which has a bulky machine mounted thereon, to prevent inadvertent falling thereof, and operate the front and rear locking units 14,16 with the other hand to permit the tabletop unit 12 to slowly move downward for folding. Hence, the user bears the combined weight of the machine and the tabletop unit 12 during the folding operation. Moreover, turning operations of the prop member 13 and the bracing member 15 have to be conducted separately, thereby rendering the folding operation inconvenient and time-consuming.